1 /* IPX driver for native Linux TCP/IP networking (UDP implementation)
3 * Contact Jan [Lace] Kratochvil <short@ucw.cz> for assistance
4 * (no "It somehow doesn't work! What should I do?" complaints, please)
5 * Special thanks to Vojtech Pavlik <vojtech@ucw.cz> for testing.
7 * Also you may see KIX - KIX kix out KaliNix (in Linux-Linux only):
8 * http://atrey.karlin.mff.cuni.cz/~short/sw/kix.c.gz
10 * Primarily based on ipx_kali.c - "IPX driver for KaliNix interface"
11 * which is probably mostly by Jay Cotton <jay@kali.net>.
12 * Parts shamelessly stolen from my KIX v0.99.2 and GGN v0.100
16 * 0.99.1 - now the default broadcast list also contains all point-to-point
17 * links with their destination peer addresses
18 * 0.99.2 - commented a bit :-)
19 * - now adds to broadcast list each host it gets some packet from
20 * which is already not covered by local physical ethernet broadcast
21 * - implemented short-signature packet format
22 * - compatibility mode for old D1X releases due to the previous bullet
26 * No network server software is needed, neither KIX nor KaliNIX.
28 * Add command line argument "-udp". In default operation D1X will send
29 * broadcasts too all the local interfaces found. But you may also use
30 * additional parameter specified after "-udp" to modify the default
31 * broadcasting style and UDP port numbers binding:
33 * ./d1x -udp [@SHIFT]=HOST_LIST Broadcast ONLY to HOST_LIST
34 * ./d1x -udp [@SHIFT]+HOST_LIST Broadcast both to local ifaces & to HOST_LIST
36 * HOST_LIST is a comma (',') separated list of HOSTs:
37 * HOST is an IPv4 address (so-called quad like 192.168.1.2) or regular hostname
38 * HOST can also be in form 'address:SHIFT'
39 * SHIFT sets the UDP port base offset (e.g. +2), can be used to run multiple
40 * clients on one host simultaneously. This SHIFT has nothing to do
41 * with the dynamic-sockets (PgUP/PgDOWN) option in Descent, it's another
42 * higher-level differentiation option.
47 * - Run D1X to participate in normal local network (Linux only, of course)
49 * ./d1x -udp @1=localhost:2 & ./d1x -udp @2=localhost:1
50 * - Run two clients simultaneously fighting each other (only each other)
52 * ./d1x -udp =192.168.4.255
53 * - Run distant Descent which will participate with remote network
54 * 192.168.4.0 with netmask 255.255.255.0 (broadcast has 192.168.4.255)
55 * - You'll have to also setup hosts in that network accordingly:
56 * ./d1x -udp +UPPER_DISTANT_MACHINE_NAME
66 #include <netinet/in.h> /* for htons & co. */
72 #include <sys/ioctl.h>
78 extern unsigned char ipx_MyAddress[10];
82 #define UDP_BASEPORT 28342
83 #define PORTSHIFT_TOLERANCE 0x100
84 #define MAX_PACKETSIZE 8192
86 /* Packet format: first is the signature { 0xD1,'X' } which can be also
87 * { 'D','1','X','u','d','p'} for old-fashioned packets.
88 * Then follows virtual socket number (as changed during PgDOWN/PgUP)
89 * in network-byte-order as 2 bytes (u_short). After such 4/8 byte header
90 * follows raw data as communicated with D1X network core functions.
93 // Length HAS TO BE 6!
94 #define D1Xudp "D1Xudp"
95 // Length HAS TO BE 2!
98 static int open_sockets = 0;
99 static int dynamic_socket = 0x401;
100 static const int val_one=1;
102 /* OUR port. Can be changed by "@X[+=]..." argument (X is the shift value)
105 static int baseport=UDP_BASEPORT;
107 /* Have we some old D1X in network and have we to maintain compatibility?
108 * FIXME: Following scenario is braindead:
109 * A (NEW) , B (OLD) , C (NEW)
110 * host A) We start new D1X. A-newcomm, B-none , C-none
111 * host B) We start OLD D1X. A-newcomm, B-oldcomm, C-none
112 * Now host A hears host B and switches: A-oldcomm, B-oldcomm, C-none
113 * host C) We start new D1X. A-oldcomm, B-oldcomm, C-newcomm
114 * Now host C hears host A/B and switches: A-oldcomm, B-oldcomm, C-oldcomm
115 * Now host B finishes: A-oldcomm, B-none , C-oldcomm
117 * But right now we have hosts A and C, both new code equipped but
118 * communicating wastefully by the OLD protocol! Bummer.
121 static char compatibility=0;
123 static int have_empty_address() {
125 for (i = 0; i < 10 && !ipx_MyAddress[i]; i++) ;
129 #define MSGHDR "IPX_udp: "
131 static void msg(const char *fmt,...)
134 fputs(MSGHDR,stdout);
141 static void chk(void *p)
144 msg("FATAL: Virtual memory exhausted!");
148 #define FAIL(m...) do { msg(#m); return -1; } while (0)
150 /* Find as much as MAX_BRDINTERFACES during local iface autoconfiguration.
151 * Note that more interfaces can be added during manual configuration
152 * or host-received-packet autoconfiguration
155 #define MAX_BRDINTERFACES 16
157 /* We require the interface to be UP and RUNNING to accept it.
160 #define IF_REQFLAGS (IFF_UP|IFF_RUNNING)
162 /* We reject any interfaces declared as LOOPBACK type.
164 #define IF_NOTFLAGS (IFF_LOOPBACK)
166 static struct sockaddr_in *broads,broadmasks[MAX_BRDINTERFACES];
167 static int broadnum,masksnum,broadsize;
169 /* We'll check whether the "broads" array of destination addresses is now
170 * full and so needs expanding.
173 static void chkbroadsize(void)
175 if (broadnum<broadsize) return;
176 broadsize=broadsize?broadsize*2:8;
177 chk(broads=realloc(broads,sizeof(*broads)*broadsize));
180 /* This function is called during init and has to grab all system interfaces
181 * and collect their broadcast-destination addresses (and their netmasks).
182 * Typically it founds only one ethernet card and so returns address in
183 * the style "192.168.1.255" with netmask "255.255.255.0".
184 * Broadcast addresses are filled into "broads", netmasks to "broadmasks".
187 /* Stolen from my GGN */
188 static int addiflist(void)
190 unsigned cnt=MAX_BRDINTERFACES,i,j;
191 struct ifconf ifconf;
193 struct sockaddr_in *sinp,*sinmp;
196 if ((sock=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP))<0)
197 FAIL("Creating socket() failure during broadcast detection: %m");
200 if (ioctl(sock,SIOCGIFCOUNT,&cnt))
201 { /* msg("Getting iterface count error: %m"); */ }
206 chk(ifconf.ifc_req=alloca((ifconf.ifc_len=cnt*sizeof(struct ifreq))));
207 if (ioctl(sock,SIOCGIFCONF,&ifconf)||ifconf.ifc_len%sizeof(struct ifreq)) {
209 FAIL("ioctl(SIOCGIFCONF) failure during broadcast detection: %m");
211 cnt=ifconf.ifc_len/sizeof(struct ifreq);
212 chk(broads=malloc(cnt*sizeof(*broads)));
214 for (i=j=0;i<cnt;i++) {
215 if (ioctl(sock,SIOCGIFFLAGS,ifconf.ifc_req+i)) {
217 FAIL("ioctl(udp,\"%s\",SIOCGIFFLAGS) error: %m",ifconf.ifc_req[i].ifr_name);
219 if (((ifconf.ifc_req[i].ifr_flags&IF_REQFLAGS)!=IF_REQFLAGS)||
220 (ifconf.ifc_req[i].ifr_flags&IF_NOTFLAGS))
222 if (ioctl(sock,(ifconf.ifc_req[i].ifr_flags&IFF_BROADCAST?SIOCGIFBRDADDR:SIOCGIFDSTADDR),ifconf.ifc_req+i)) {
224 FAIL("ioctl(udp,\"%s\",SIOCGIF{DST/BRD}ADDR) error: %m",ifconf.ifc_req[i].ifr_name);
227 sinp =(struct sockaddr_in *)&ifconf.ifc_req[i].ifr_broadaddr;
228 sinmp=(struct sockaddr_in *)&ifconf.ifc_req[i].ifr_netmask ;
229 if (sinp->sin_family!=AF_INET || sinmp->sin_family!=AF_INET) continue;
231 broads[j].sin_port=UDP_BASEPORT; //FIXME: No possibility to override from cmdline
232 broadmasks[j]=*sinmp;
240 #define addreq(a,b) ((a).sin_port==(b).sin_port&&(a).sin_addr.s_addr==(b).sin_addr.s_addr)
242 /* Previous function addiflist() can (and probably will) report multiple
243 * same addresses. On some Linux boxes is present both device "eth0" and
244 * "dummy0" with the same IP addreesses - we'll filter it here.
247 static void unifyiflist(void)
251 for (s=0;s<broadnum;s++) {
253 if (addreq(broads[s],broads[i])) break;
254 if (i>=s) broads[d++]=broads[s];
259 static unsigned char qhbuf[6];
261 /* Parse PORTSHIFT numeric parameter
264 static void portshift(const char *cs)
267 unsigned short ports=0;
270 if (port<-PORTSHIFT_TOLERANCE || port>+PORTSHIFT_TOLERANCE)
271 msg("Invalid portshift in \"%s\", tolerance is +/-%d",cs,PORTSHIFT_TOLERANCE);
272 else ports=htons(port);
273 memcpy(qhbuf+4,&ports,2);
276 /* Do hostname resolve on name "buf" and return the address in buffer "qhbuf".
278 static unsigned char *queryhost(char *buf)
284 if ((s=strrchr(buf,':'))) {
289 else memset(qhbuf+4,0,2);
290 he=gethostbyname((char *)buf);
293 msg("Error resolving my hostname \"%s\"",buf);
296 if (he->h_addrtype!=AF_INET || he->h_length!=4) {
297 msg("Error parsing resolved my hostname \"%s\"",buf);
300 if (!*he->h_addr_list) {
301 msg("My resolved hostname \"%s\" address list empty",buf);
304 memcpy(qhbuf,(*he->h_addr_list),4);
308 /* Dump raw form of IP address/port by fancy output to user
310 static void dumpraddr(unsigned char *a)
313 printf("[%u.%u.%u.%u]",a[0],a[1],a[2],a[3]);
314 port=(signed short)ntohs(*(unsigned short *)(a+4));
315 if (port) printf(":%+d",port);
318 /* Like dumpraddr() but for structure "sockaddr_in"
321 static void dumpaddr(struct sockaddr_in *sin)
323 unsigned short ports;
325 memcpy(qhbuf+0,&sin->sin_addr,4);
326 ports=htons(((short)ntohs(sin->sin_port))-UDP_BASEPORT);
327 memcpy(qhbuf+4,&ports,2);
331 /* Startup... Uninteresting parsing...
334 static int ipx_udp_GetMyAddress(void) {
340 if (!have_empty_address())
343 if (!((i=FindArg("-udp")) && (s=Args[i+1]) && (*s=='=' || *s=='+' || *s=='@'))) s=NULL;
345 if (gethostname(buf,sizeof(buf))) FAIL("Error getting my hostname");
346 if (!(queryhost(buf))) FAIL("Querying my own hostname \"%s\"",buf);
348 if (s) while (*s=='@') {
350 while (isdigit(*s)) s++;
353 memset(ipx_MyAddress+0,0,4);
354 memcpy(ipx_MyAddress+4,qhbuf,6);
355 baseport+=(short)ntohs(*(unsigned short *)(qhbuf+4));
357 if (!s || (s && !*s)) addiflist();
359 if (*s=='+') addiflist();
362 struct sockaddr_in *sin;
363 while (isspace(*s)) s++;
365 for (s2=s;*s2 && *s2!=',';s2++);
366 chk(ns=malloc(s2-s+1));
369 if (!queryhost(ns)) msg("Ignored broadcast-destination \"%s\" as being invalid",ns);
372 sin=broads+(broadnum++);
373 sin->sin_family=AF_INET;
374 memcpy(&sin->sin_addr,qhbuf+0,4);
375 sin->sin_port=htons(((short)ntohs(*(unsigned short *)(qhbuf+4)))+UDP_BASEPORT);
382 printf(MSGHDR "Using TCP/IP address ");
383 dumpraddr(ipx_MyAddress+4);
386 printf(MSGHDR "Using %u broadcast-dest%s:",broadnum,(broadnum==1?"":"s"));
387 for (i=0;i<broadnum;i++) {
397 /* We should probably avoid such insanity here as during PgUP/PgDOWN
398 * (virtual port number change) we wastefully destroy/create the same
399 * socket here (binded always to "baseport"). FIXME.
400 * "open_sockets" can be only 0 or 1 anyway.
403 static int ipx_udp_OpenSocket(ipx_socket_t *sk, int port) {
404 struct sockaddr_in sin;
407 if (have_empty_address())
408 if (ipx_udp_GetMyAddress() < 0) FAIL("Error getting my address");
410 msg("OpenSocket on D1X socket port %d",port);
413 port = dynamic_socket++;
415 if ((sk->fd = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP)) < 0) {
417 FAIL("socket() creation failed on port %d: %m",port);
419 if (setsockopt(sk->fd,SOL_SOCKET,SO_BROADCAST,&val_one,sizeof(val_one))) {
420 if (close(sk->fd)) msg("close() failed during error recovery: %m");
422 FAIL("setsockopt(SO_BROADCAST) failed: %m");
424 sin.sin_family=AF_INET;
425 sin.sin_addr.s_addr=htonl(INADDR_ANY);
426 sin.sin_port=htons(baseport);
427 if (bind(sk->fd,(struct sockaddr *)&sin,sizeof(sin))) {
428 if (close(sk->fd)) msg("close() failed during error recovery: %m");
430 FAIL("bind() to UDP port %d failed: %m",baseport);
438 /* The same comment as in previous "ipx_udp_OpenSocket"...
441 static void ipx_udp_CloseSocket(ipx_socket_t *mysock) {
443 msg("close w/o open");
446 msg("CloseSocket on D1X socket port %d",mysock->socket);
447 if (close(mysock->fd))
448 msg("close() failed on CloseSocket D1X socket port %d: %m",mysock->socket);
450 if (--open_sockets) {
451 msg("(closesocket) %d sockets left", open_sockets);
456 /* Here we'll send the packet to our host. If it is unicast packet, send
457 * it to IP address/port as retrieved from IPX address. Otherwise (broadcast)
458 * we'll repeat the same data to each host in our broadcasting list.
461 static int ipx_udp_SendPacket(ipx_socket_t *mysock, IPXPacket_t *IPXHeader,
462 u_char *data, int dataLen) {
463 struct sockaddr_in toaddr,*dest;
469 msg("SendPacket enter, dataLen=%d",dataLen);
471 if (dataLen<0 || dataLen>MAX_PACKETSIZE) return -1;
472 chk(buf=alloca(8+dataLen));
473 if (compatibility) memcpy(buf+0,D1Xudp,6),buf+=6;
474 else memcpy(buf+0,D1Xid ,2),buf+=2;
475 memcpy(buf+0,IPXHeader->Destination.Socket,2);
476 memcpy(buf+2,data,dataLen);
478 toaddr.sin_family=AF_INET;
479 memcpy(&toaddr.sin_addr,IPXHeader->Destination.Node+0,4);
480 toaddr.sin_port=htons(((short)ntohs(*(unsigned short *)(IPXHeader->Destination.Node+4)))+UDP_BASEPORT);
482 for (bcast=(toaddr.sin_addr.s_addr==htonl(INADDR_BROADCAST)?0:-1);bcast<broadnum;bcast++) {
483 if (bcast>=0) dest=broads+bcast;
487 printf(MSGHDR "sendto((%d),Node=[4] %02X %02X,Socket=%02X %02X,s_port=%u,",
489 IPXHeader->Destination.Node [4],IPXHeader->Destination.Node [5],
490 IPXHeader->Destination.Socket[0],IPXHeader->Destination.Socket[1],
491 ntohs(dest->sin_port));
495 i=sendto(mysock->fd,buf-(compatibility?6:2),(compatibility?8:4)+dataLen,
496 0,(struct sockaddr *)dest,sizeof(*dest));
497 if (bcast==-1) return (i<8?-1:i-8);
502 /* Here we will receive new packet to the given buffer. Both formats of packets
503 * are supported, we fallback to old format when first obsolete packet is seen.
504 * If the (valid) packet is received from unknown host, we will add it to our
505 * broadcasting list. FIXME: For now such autoconfigured hosts are NEVER removed.
508 static int ipx_udp_ReceivePacket(ipx_socket_t *s, char *outbuf, int outbufsize,
509 struct ipx_recv_data *rd) {
511 struct sockaddr_in fromaddr;
512 int fromaddrsize=sizeof(fromaddr);
513 unsigned short ports;
517 if ((size=recvfrom(s->fd,outbuf,outbufsize,0,(struct sockaddr *)&fromaddr,&fromaddrsize))<0)
520 printf(MSGHDR "recvfrom((%d-8=%d),",size,size-8);
524 if (fromaddr.sin_family!=AF_INET) return -1;
525 if (size<4) return -1;
526 if (memcmp(outbuf+0,D1Xid,2)) {
527 if (size<8 || memcmp(outbuf+0,D1Xudp,6)) return -1;
528 if (!compatibility) {
530 fputs(MSGHDR "Received obsolete packet from ",stdout);
532 puts(", upgrade that machine.\n" MSGHDR "Turning on compatibility mode...");
538 /* Lace: (dst_socket & src_socket) should be network-byte-order by comment in include/ipx_drv.h */
539 /* This behaviour presented here is broken. It is not used anywhere, so why bother? */
540 rd->src_socket = ntohs(*(unsigned short *)(outbuf+offs));
541 if (rd->src_socket != s->socket) {
543 msg(" - pkt was dropped (dst=%d,my=%d)",rd->src_socket,s->socket);
547 rd->dst_socket = s->socket;
549 for (i=0;i<broadnum;i++) {
551 if (addreq(fromaddr,broads[i])) break;
554 if (fromaddr.sin_port==broads[i].sin_port
555 &&( fromaddr.sin_addr.s_addr & broadmasks[i].sin_addr.s_addr)
556 ==(broads[i].sin_addr.s_addr & broadmasks[i].sin_addr.s_addr)) break;
561 broads[broadnum++]=fromaddr;
562 fputs(MSGHDR "Adding host ",stdout);
564 puts(" to broadcasting address list");
567 memmove(outbuf,outbuf+offs+2,size-(offs+2));
570 memcpy(rd->src_node+0,&fromaddr.sin_addr,4);
571 ports=htons(ntohs(fromaddr.sin_port)-UDP_BASEPORT);
572 memcpy(rd->src_node+4,&ports,2);
573 memset(rd->src_network, 0, 4);
576 printf(MSGHDR "ReceivePacket: size=%d,from=",size);
577 dumpraddr(rd->src_node);
584 struct ipx_driver ipx_udp = {
585 ipx_udp_GetMyAddress,
589 ipx_udp_ReceivePacket,
590 ipx_general_PacketReady
593 #endif // __ENV_LINUX__